Navigation device employing an electret vibration sensor

• US 5,827,965 A
• Filed: 01/23/1997
• Issued: 10/27/1998
• Est. Priority Date: 06/20/1994
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kishigami, Jun, Nakagawa, Yoshimori
• Primary Examiner(s): Oda, Christine K.
• Application Number:
  US08/787,802
• Time in Patent Office: 642 Days
• Field of Search: 73/488, 73/178 T, 73/178 R, 73/185, 73/491, 73/498, 73/514.32, 73/514.23
• US Class Current: 73/488
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G01H 11/06 by electric means
• CPC Class Codes: G01P 15/125 by capacitive pick-up

Abstract

A vibration sensor includes a substrate (5), a plate-like diaphragm (3) forming a capacitor, and holding means (2), (4), (6) for holding the diaphragm so as to be movable in parallel to the substrate; The diaphragm includes a plurality of flexible displacement portions (3c), (3d) for enabling the supporting portion of the diaphragm to be movable in parallel to the substrate. When vibrations are applied to the vibration sensor, the diaphragm portion of the diaphragm is vibrated and electrostatic capacity formed between the substrate and the diaphragm is changed based on the vibrations. Vibrations are detected on the basis of the change of electrostatic capacity. Since the vibration sensor includes the flexible displacement portions, the diaphragm becomes difficult to be vibrated due to a sound pressure and a vibration detected output can be prevented from being disturbed by the sound pressure.

Claims

1. A navigation apparatus comprising:

a position detecting circuit which detects a current position of a navigation object;

a vibration sensor which is mechanically coupled to said navigation object, said vibration sensor comprising;

a substrate,

a diaphragm, said diaphragm comprising;

a central diaphragm portion,

a supporting portion disposed around the periphery of said central diaphragm portion,

a plurality of elongated openings disposed radially at equal intervals around a circumference of said central diaphragm portion between said central diaphragm portion and said supporting portion, and

a plurality of flexible displacement portions defined between said openings for coupling said diaphragm portion and said supporting portion such that said central diaphragm portion is able to move relative to said substrate, said central diaphragm portion being spaced from said substrate by a predetermined distance, and

an electret film being disposed either on said substrate on a surface opposing said diaphragm or on said diaphragm on a surface opposing said substrate;

a reproducing circuit for reading and reproducing map data from memory;

a display for displaying thereon said map data supplied thereto from said reproducing circuit; and

a control circuit controlling operation of said reproducing circuit in response to output from at least one of said vibration sensor and said position detecting circuit.

2. A navigation apparatus as claimed in claim 1, further comprising a speed detecting circuit which receives input from said vibration sensor and determines therefrom the speed of said navigation object, output from said speed detecting circuit being provided to said control circuit.

3. A navigation apparatus as claimed in claim 1, wherein said position detecting circuit comprises an antenna for received transmissions from a positioning satellite.

4. A navigation apparatus as claimed in claim 1, wherein said reproducing circuit is a disc player and said memory is a CD ROM.

5. A navigation apparatus as claimed in claim 1, further comprising a console for providing user input to said control circuit.

6. A navigation apparatus as claimed in claim 1, wherein said display is a liquid crystal display.

7. A navigation apparatus comprising:

position detecting means for detecting a current position of a navigation object;

a vibration sensing means which is mechanically coupled to said navigation object, said vibration sensing means comprising;

a substrate,

a diaphragm comprising;

a central diaphragm portion,

a supporting portion for supporting said central diaphragm portion such that said central diaphragm portion becomes is able to move relative to said substrate, said central diaphragm portion being spaced from said substrate by a predetermined distance, and

a plurality of elongated openings disposed radially at equal intervals around a circumference of said central diaphragm portion between said central diaphragm portion and said supporting portion, and

an electret film being disposed either on said substrate on a surface opposing said diaphragm or on said diaphragm on a surface opposing said substrate;

reproducing means for reading and reproducing map data;

display means for displaying thereon said map data supplied thereto from said reproducing means; and

control means for controlling an operation of said reproducing means in response to output from at least one of said vibration sensing means and said position detecting means.

8. A navigation apparatus as claimed in claim 7, further comprising a speed detecting means which receives input from said vibration sensing means and determines therefrom the speed of said navigation object, output from said speed detecting means being provided to said control means.

9. A navigation apparatus as claimed in claim 7, wherein said position detecting means comprises an antenna for received transmissions from a positioning satellite.

10. A navigation apparatus as claimed in claim 7, wherein said reproducing means is an optical disc reading means and said memory is a CD ROM.

11. A navigation apparatus as claimed in claim 7, further comprising an input means for providing user input to said control means.

12. A navigation apparatus as claimed in claim 7, wherein said display means comprises a liquid crystal display.